Secretory Leukocyte Protease Inhibitor Protein (SLPI) is an Novel Early Induced Gene in the Rat Liver Regeneration

Liver regeneration has been extensively studied but its molecular mechanism is still poorly understood. We applied the model of 70% partial hepatectomy (PH) to study liver regeneration in the rat by adult hepatocytes proliferation. Serial Analysis of Gene Expression (SAGE) was employed to study the gene expression profile at an early stage of regeneration (8 hours after PH). In addition, RNA extracted from livers of sham operated and normal animals was analysed by the same technique. Comparison of the three different transcriptomes identified genes differentially regulated in the regeneration process: 38 genes were up-regulated and 19 genes were down-regulated. The SAGE results were verified by studying the kinetic of those single genes by Real Time PCR using RNA extracted from livers from two separate series of PH animals and sham animals. So far we have characterised 10 genes kinetically up-regulated and 8 genes kinetically down-regulated. Among already known and characterized as up-regulated genes (e.g. IGFBP1, Angiotensinogen, CTGF, Jun-B) a strikingly high up-regulation was found for secretory leukocyte protease inhibitor (SLPI) which was induced early after 4 hours the PH. The functional role of this important gene will be further analysed.

Key words

Liver Regeneration - Partial Hepatectomy - SAGE